I. Field of the Invention
The present invention relates to burial vaults, and, more particularly, to a composite burial vault comprising a plastic resinous liner with a concrete mechanically bonded to one surface thereof.
II. Description of the Prior Art
Composite burial vaults, such as that described in U.S. Pat. No. 3,439,461 issued to Chandler et al on Apr. 22, 1969, are relatively new in the field. Such burial vaults typically comprise a plastic resinous liner which is coated first wtih an adhesive and then with concrete. Such composite burial vaults have been found to be advantageous in that the concrete provides structural rigidity, while the plastic resinous liner if it is exterior of the concrete provides a water resistant wall unlike the more porous cement.
In some arrangements, the liner is for appearance and protection disposed interiorly of the burial vault. In still other arrangements, a resinous inner and resinous outer liner are provided with the concrete formed therebetween. Although such composite burial vaults have been well accepted in the trade, such burial vaults also have disadvantages of which it is the object of the present invention to eliminate.
The primary disadvantage with the prior art composite burial vaults is that an adhesive must be applied to the liner prior to pouring the concrete into the mold. The adhesive is not only expensive to purchase, but also is expensive to apply to the liner in that typically twenty to thirty minutes are required to completely coat the liner with the adhesive. A further disadvantage of the use of an adhesive between the liner and the concrete is that when the wet concrete is poured against the tacky adhesive, the concrete flow tends to rub the adhesive off the liner. When the adhesive is removed by the concrete flow, only a loose, and therefore undesirable, bond is formed between the liner and the concrete.
Another problem with the previously known liner-adhesive-concrete bond in a composite burial vault is that such a bond requires a relatively high amount of water for the liner-adhesive bond. It has been found that thermal expansion and contraction of the bond will often crack the resinous liner, both before and after the burial vault is finally placed into the ground. A cracked burial vault functions ineffectively and is therefore undesirable.
An associated problem has arisen as the use of composite burial vaults have become more widespread. Namely, various companies have developed and manufacture vacuum formed resinous liners and sell such liners to funeral homes, cemeteries, or the like. The composite burial vaults are assembled by the purchaser after the liner is received by the purchaser. The vacuum formed liners, however, are brittle and often break or crack en route to their destination. The high breakage rate of vacuum formed liners is very undesirable and unnecessarily increases the cost of the composite burial vault.